Muscarinic M1, M3, Nicotinic,GABAA and GABAB Receptor ...

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Discussion
al., 1992), it has the ability to affect neuronal migration (Komuro & Rakic, 1996)
as well as other developmental functions such as apoptosis (Sastry & Rao, 2000).
In the present study, the up regulation of α7 nicotinic receptor is
associated with altered and hypofunction of the receptor induced by glucose
deprivation during hypoglycemia and diabetes which also leads to cognitive and
memory deficits. Nicotinic receptor activation has been reported to improve
performance in tests measuring several forms of learning and memory and its
effects appear to be most robust for working memory (Levin 1992; Levin &
Simon 1998). Present findings showed that the behavioural anomalities observed
in glucose deprived /hypoglycemic rats are attributed to impaired function of α7
nicotinic receptors. These receptors mediate fast synaptic transmission (Alkondon
et al., 1998; Frazier et al., 1998; Chang & Berg, 1999) and modulation of synaptic
transmission mediated by transmitters such as acetylcholine, dopamine, glutamate,
gamma aminobutyric acid (GABA) (MacDermott et al., 1999) norepinephrine and
and serotonin which is altered by recurrent hypoglycemic attacks in diabetic and
non-diabetic rats.
CENTRAL GABA RECEPTOR ALTERATIONS IN EXPERIMENTAL
RATS
Symptoms associated with hypoglycemic are related to the release of
catecholamines, however, at times, transient neurological deficits, presumably
resulting from a low intracerebral glucose concentration, accompany the typical
clinical picture. These transient neurological deficits may be generalized such as
confusion, motor restlessness, hypotonia and generalized seizures (Lahat, 1995).
Epileptic episodes induced by hypoglycemia are the cause of neurological deficits
(Wayne et al., 1990). GABA, the major inhibitory neurotransmitter in the CNS
(Sivilotti & Nistri, 1991) plays an important role in seizure generation. Excitatory
and inhibitory neurotransmission in the CNS is mediated mainly by glutamate and
GABA, respectively. A dysfunction of any of these neurotransmitter systems is